Hood adjustment

A simple question to the mechanically savvy. My passenger side winsshield wiper arm rubs against the underside of the hood when the wiper is in the stowed condition. I tried tightening the nut on the wiper motor shaft to eliminate any play, but the wiper still rubs. Is it possible to gain some clearance between the wiper arm and the hood by adjusting the height of the hood? If so, where do I make those adjustment on this style of hood (forward tilt).

The problem is your hood has lost its mid-section "bow". I suppose you could say it's sagged, but not from gravity, rather from the air pressure on the hood as it's driven over many years. You _could_ remake some clearance by placing something (4x4, perhaps?) in the middle window-side edge and with two people, re-bend the hood (carefully!). Not a permanent fix however, the hood will re-sag.

I opted to remove the wiper arm, and reposition it so when it was in the stopped position, it wouldn't contact the hood. A longer term fix, but - I don't know at which point the hood will no longer sag, so you may find you have to re-fix the wiper arm or later, or resort to re-bowing the hood, if you do what I did.

The hood has not changed shape over the years, the wiper arm has. It has experienced creep from the spring pressure against it and the windshield. This is very very common, but I have never tried to fix it on a BMW. I'll try on my wagon and get back to you.

The hood has not changed shape over the years, the wiper arm has. It has experienced creep from the spring pressure against it and the windshield. This is very very common, but I have never tried to fix it on a BMW. I'll try on my wagon and get back to you.

Just to clarify, the creep occurs in 1) the splines of the wiper arm (where it mounts to motor shaft) or 2) the wiper arm between the splines and the pivot spring?

I think the creep appears to occur on the long portion of the arm, the part that is hitting the hood. Like I said, I have not tried to fix it, but when I do I'll post how it turns out. We have to recurve Volvo wiper arms all the time. They don't hit the hood, but they creep to the point that the blades don't make proper contact with the windshield. If I could get my hands on a new arm to compare, I would. The new ones are $65, so maybe I'll just buy one.

I think the creep appears to occur on the long portion of the arm, the part that is hitting the hood. Like I said, I have not tried to fix it, but when I do I'll post how it turns out. We have to recurve Volvo wiper arms all the time. They don't hit the hood, but they creep to the point that the blades don't make proper contact with the windshield. If I could get my hands on a new arm to compare, I would. The new ones are $65, so maybe I'll just buy one.

Paul,

My wiper arm is contacting the hood at a point which is inboard of the tensioning spring mechanism. That is between the spring assembly and the splined mounting pivot (where the motor shaft connects). I have no problem with the wiper maintaining contact with the windshield. I'll try to post some pictures in a day, or so.

I know where it is hitting- that is where they all do that. I didn't mean the long steel portion of the arm, I meant the long aluminum portion of the arm just after the part that bolts to the spline. I think the force of the wiper against the windshield causes the aluminum part of the arm to bow and slowly deform over time. I have not seen any with issues with wiper blade to windshield contact, though, but I would like to make mine not hit the hood.

I think the creep appears to occur on the long portion of the arm, the part that is hitting the hood. Like I said, I have not tried to fix it, but when I do I'll post how it turns out. We have to recurve Volvo wiper arms all the time. They don't hit the hood, but they creep to the point that the blades don't make proper contact with the windshield. If I could get my hands on a new arm to compare, I would. The new ones are $65, so maybe I'll just buy one.

Did you every buy a new wiper arm? If so, does it clear the hood? And if so, by how much?

I'm far too cheap to buy a new one. I was able to tweak it a little in a vise, but I wouldn't recommend this. I have one more theory to test as well. I'll get back to you after I work on the car next week.